There is such an automated warehouse consisting of a plurality of shelves and an inward/outward delivery device like the one presented by Japanese Laid-Open Patent Application Publication No. 63-218406 (1988), which uses a crane functioning as an inward/outward delivery device having a pair of front and rear struts or a single strut erected on a bottom frame or a truck in conjunction with an elevating carriage guided to said strut(s).
Each strut has square cylindrical transverse section and a groove-shaped guide rail in the center of front-rear line or right-left line. In addition, each strut has a plurality of L-shaped plates projecting themselves to the left and to the right or in the forward and backward directions, where these L-shaped plates extend themselves from respective corners. In order to fix parts, a rail groove is formed in respective L-shaped plates. Each strut is composed of an integrally extruded member having transverse section with symmetrically arranged front-rear and right-left formation.
When introducing a pair of struts for example, those double struts set to front and rear positions are erected on a bottom frame by orienting the guide rail in the front-rear direction, i.e., in the running direction. Next, a guide roller is brought into contact with any surface that faces the elevating carriage side (i.e., in the front-rear direction) among those surfaces forming the guide rail part, where the guide roller prevents front-rear-directional swing from the elevating carriage from occurrence. At the same time, another guide roller is brought into contact with a pair of surfaces positioned on both sides, where the latter guide roller prevents right-left-directional swing from the elevating carriage from occurrence.
On the other hand, when introducing a single strut, the guide rail is erected on a truck in the right-left direction. Next, a guide roller is brought into contact with a pair of surfaces facing the front-rear direction among those surfaces forming the guide rail part, where the guide roller prevents front-rear-directional swing from the elevating carriage from occurrence At the same time, another guide roller is brought into contact with a surface facing the right-left direction, where the latter guide roller prevents right-left-directional swing from the elevating carriage from occurrence.
However, when introducing the double struts according to the above exemplified prior art, since the L-shaped plates project themselves solely in the right-left direction, these L-shaped plates are by no means instrumental to reinforce the double struts in the front-rear direction. In consequence, these struts are apt to tilt themselves in the front-rear direction whenever accelerating or decelerating or discontinuing operating movement of the crane. Likewise, when introducing a single strut to the above structure, since the L-shaped plate projects itself solely in the right-left direction, the L-shaped plate is by no means instrumental to reinforce the strut in the right-left direction. In consequence, the single strut is apt to tilt itself in the right-left direction whenever delivering products into and out of a warehouse by operating a projected fork of a forklift truck.
Furthermore, since the direction of the single strut and the double struts must compulsorily be shifted by 90 degrees from each other, error easily occurs while erecting the struts on the bottom frame or the truck, and yet, much labor and time must be spent before completing the strut-erecting work.
Another exemplified structure is presented by Japanese Patent Publication No. 53-3529 (1978) for example. Concretely, a shelf-loading lift functioning as a delivery device is equipped with a double-barrel winding machine secured thereto by projecting itself from external surface of a vertical frame. A suspension rope being wound or unwound via rotation of each drum of the double-barrel winding machine is swingably separated into front and rear parts by means of an upper pulley set to an upper frame and then interlinked with each guide frame of a loading platform. The above-cited double-barrel winding machine causes each barrel to pivot on the right-left-directional axis.
Nevertheless, according to the structure of the above-cited prior art, the suspension rope extended from the upper pulley to respective barrels is positioned by way of externally being exposed along external surface of the vertical frame. Thus, it not only generates rather poor appearance, but it also causes maintenance operator to easily come into contact with the suspension rope to incur potential hazard. To dispose of this problem, there is an idea to pass the suspension rope through a vertical cylindrical frame and then draw out the rope from the cylindrical frame body at the position of the double-barrel winding machine. However, when executing this method, cutout portion must be provided for the rope-extracting position. This in turn involves troublesome processing steps and causes strength to decrease, and yet, much labor and time must be spent to pass the suspension rope through the cylindrical frame body.
Furthermore, since each barrel has substantial length in the right-left direction and long distance from the upper pulley, the suspension rope swings itself by a wide amplitude to the left and to the right while being wound and unwound, thus generating problem in terms of security. Conventionally, such a suspension rope is composed of a plurality of wires impregnated or adhered with oil, and thus, when the rope swings, oil easily scatters to cause peripheral regions to be stained.
Furthermore, there is another structure for guiding upper part of a crane exemplified in Japanese Laid-Open Patent Application Publication No. 62-290609 (1987). According to this prior art, a warehouse crane is movably supported by a guide-rail unit installed on floor surface. An overhang member is provided by way of extending itself in the horizontal direction from an upper frame. A pair of vertical shaft roller functioning to inhibit swing motion and nipping an upper guide-rail unit from both sides are pivotally supported on the overhang member in such a state without upwardly projecting itself from the upper surface of the upper frame. In addition, a guide plate is also provided, which incorporates a recess for accommodating the upper guide rail unit for engagement therewith.
According to the structure of the above-exemplified art, upper surface of the upper frame can be brought to a position closest to a ceiling surface or a beam member that supports the upper guide rail. In addition, the above structure can promote storage efficiency of the operating warehouse by minimizing vertical-directional dead space including the upper frame. Furthermore, even in the event that the above-referred vertical shaft roller functioning to inhibit swing motion ever falls off, the crane can securely be prevented from falling to the left or to the right by virtue of proper engagement of recessed domain of the guide plate with the upper guide rail unit.
Nevertheless, according to the structure of the above exemplified art, since the center position of the crane is not coincident with the center of the guide rail unit, in other words, since the centers of the crane and the guide rail unit significantly deviate from each other in the right-left direction, when stopper action is generated as a result of forcible contact of the swing-motion-inhibiting vertical shaft roller with the upper guide rail unit caused by biased load took place while delivering products into and from a warehouse by protruding a load transferring means in the lateral direction, the crane itself may incur distortion by effect of dispersed force. In addition, when stopper action is generated, substantial bending moment may act upon connecting part (joint portion) of the overhang member to break off the connection. If the connecting part were torn off, the guide plate will totally lose own function to prevent the crane from falling off.
Furthermore, there is such a structure for guiding lower part of a crane exemplified in Japanese Laid-Open Patent Application Publication No. 5-246509 (1993). According to this prior art, a delivery device is supportedly guided to a floor rail unit via drive wheels, follower wheels, and guide wheels. A detectable object having a detectable surface oriented to lateral direction is installed on the floor rail unit. A running-movement-controlling detection device is secured to the bottom of the delivery device, where the delivery device can freely face the detectable object from lateral side. According to this structure, products can be delivered from the delivery device to corresponding shelves or vice versa by combining travelling movement of the delivery device running on a predetermined route along front surface of shelves with vertical movement of an elevator and forward/backward movement of a delivery tool in lateral direction. Travelling movement of the delivery device can be controlled by causing the detection device to detect the object of detection.
Nevertheless, according to the structure of the above-exemplified art, detectable surface of the detectable object projects in the external lateral direction from lateral surface of the upper plate on the floor rail. This in turn permits dust of worn elements of wheels to easily deposit on the detectable surface to stain the detectable surface to consequently lower detection precision, thus eventually failing to correctly and stably control the whole system operation including travelling movement of the delivery device. Once such defect occurs, it will cause wheels of the other side to float themselves from floor rails by way of availing either side of front and rear wheels as supporting point while the delivery device accelerates or decelerates own moving speed or travels at a high speed or stops own movement in case of emergency. In an extreme case, wheels of the delivery device may run off from the floor rails or the delivery device may overturn itself.